public static string SendMail(string from, string to, string subject, string msg)
        {
            MailMessage mssg = new MailMessage(from, to, subject, msg);
            mssg.IsBodyHtml = true;
            SmtpClient client = new SmtpClient(ConfigurationManager.AppSettings["MailServer"].Trim().Replace("''", "'"));
            
            try
            {
                client.Send(mssg);
                return ("true");
            }
            catch
            {
                return ("false");
            }
        }

 
<configuration> 
  <system.net> 
    <mailSettings> 
      <smtp deliveryMethod="specifiedPickupDirectory"> 
        <specifiedPickupDirectory pickupDirectoryLocation="c:\maildrop" /> 
      </smtp> 
    </mailSettings> 
  </system.net> 
</configuration> 

 
<system.net> 
    <mailSettings> 
      <smtp deliveryMethod="Network"> 
        <network host="smtp.xxxx.com" /> 
      </smtp> 
    </mailSettings> 
  </system.net>